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Super Heavy has splashed down in The Gulf of Mexico

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Re: Super Heavy has splashed down in The Gulf of Mexico

#551

Post by ericcumbee »

kevstev wrote: post #230
themgt wrote: post #94

Earlier quoted context omitted.

That was seriously some of the most dramatic television I've ever watched. Video of Starship being melted/torn apart by supersonic plasma, the broadcast stream dying multiple times maybe due to ship destruction, then finally back online, peeking through the cracked camera to see the nearly destroyed grid fin STILL ACTUATING. The announcers laughing about the ship being "maybe held together by some nuts and bolts" and…

I have never rooted for a flap so hard, and likely never will. I am ready to buy flap merch. The energy of the SpaceX employees gave me goosebumps, this was great, it was hard not to get caught up in it- you know this is the culmination of years of hard work that is mostly theoretical until tests like these.

hearing the spacex is half the fun. Its fun to hear them cheer. and then hearing the Gasps and "ooooooh"s and wondering what do they know thats happening.

Re: Super Heavy has splashed down in The Gulf of Mexico

#552

Post by KiwiJohnno »

aeternum wrote: post #500
Zigurd wrote: post #450

Earlier quoted context omitted.

That doesn't work IRL. Space is insanely unforgiving. While Starship has a vastly better chance than STS had of achieving rapid reusability, you really can't launch with a rocket that isn't up to spec because adding robustness adds weight. Unlike a multi-stage expendable rocket, Starship uses all its fuel to get to orbit. To go to the moon or beyond, it requires refueling by several other Starships that also just get…

The vast majority of the weight however is oxidizer which you could theoretically eliminate since the rocket is surrounded with various amounts of oxygen depending on launch trajectory. A scramjet power first stage for example could overcome the tyranny of the rocket equation (at least on earth).

Not necessarily as much as you think.

The issue is orbital velocity is an absolutely bonkers high velocity. Nothing can even come close to that velocity in the atmosphere. The SR-71, fastest air-breathing aircraft ever flow topped out at around 1/9th of orbital velocity. Yes scramjets could certainly beat that speed, once they are developed but even if that doubles the speed of a SR-71 (which already was pushing the limits of heating) then you are still only doing 1/4th of the speed you need for orbit.

So you have a bit of a catch-22 situation - You can have plenty of oxygen for your engines all around you, or you can have the speed you need for orbit - But not both at the same time. Yes, a scramjet can reduce the amount of oxidizer required (by a lot) but to do this you need the extra weight of wings and everything else you need for proper aerodynamic flight.

Re: Super Heavy has splashed down in The Gulf of Mexico

#553

Post by pdonis »

stctw wrote: post #406
amanaplanacanal wrote: post #391

Earlier quoted context omitted.

Firebombing whole cities in Europe and Japan is still a black mark in US history. It’s really hard for me to get “holier than thou” on other terror campaigns when I remember that.

It's easy to say that now. Have you lived through unrestricted, total warfare, where one side intends to conquer a continent or the world, invades without provocation, and won't stop until brought to submission through extreme force? The Allies did not initiate war and did not want war. How many of your country's people should you sacrifice to end a war of aggression started by the enemy? Should you not use the means…

> one side intends to conquer a continent or the world, invades without provocation, and won't stop until brought to submission through extreme force? The Allies did not initiate war and did not want war.

"The Allies" included the Soviet Union, which did initiate war--against Finland, against Poland, against Japan (this in the 1930s, before historians say WW II started)--and wanted even more war, hoping that all of the capitalist countries would destroy each other and leave the USSR to take over. And as others have pointed out, the USSR ended up in control of Eastern Europe, which was supposed to be liberated from tyranny--that was the original reason for Britain and France declaring war on Germany when Poland was invaded--so WW II actually failed at its primary objective. Even if you make the argument that Allied firebombing raids were a justified war measure, that argument only works if the war succeeds at its objective. If it fails, that argument falls to the ground.

Re: Super Heavy has splashed down in The Gulf of Mexico

#554

Post by avmich »

jiggawatts wrote: post #538
avmich wrote: post #437

Earlier quoted context omitted.

No, I didn't complain about the front row seat :) calm down. And yes, SpaceX is the trend setter in the industry right now, there is no question that their approaches are more modern. Having said that, cameras today can be really small. Not a big box. Lenses or their protectors can be rather, well, protective (I'm thinking about moissanite here, but may be better solutions are possible). And I didn't see lots of came…

Sapphire optical windows are cheaper than you think, but in this case the problem seemed to be that the lens was splashed by molten metal that then solidified.

This could be solved by replacing the protection (I think solutions like that are rather common, mechanically move the flat transparent screen) or by just switching to another camera.

Re: Super Heavy has splashed down in The Gulf of Mexico

#555

Post by FredPret »

xcv123 wrote: post #544
FredPret wrote: post #541

Earlier quoted context omitted.

Conditional surrender would have been completely unacceptable given that they were the aggressor and had a million troops in China, and wanted to hold on to their conquests after the war. Even after the first nuke they didn't surrender. It took the emperor speaking up - for the first time ever - after the second nuke, and even then the military junta tried to stop it. Your points about the Communists stand, but keep…

> Conditional surrender would have been completely unacceptable And some would argue that nuking entire cities is completely unacceptable.

Allied options were:

1. Invade. Expected Allied casualties of 300k all the way to much more than a million. Expected Japanese casualties: tens of millions, perhaps up to literally all of them. Previous Japanese strongholds fought to the last man, earlier in the war the Allies invaded an island with 11000 Japanese soldiers, and I think 47 of those eventually surrendered. The rest died. The civilian populations on these islands infamously committed suicide in huge numbers rather than be captured by the Allies. How much harder would an invasion of the home islands be!? The Japanese government issued an order that every single person must fight to the death.

2. Starve them out. The allies had submarines all around Japan and completely blocked all food and oil imports. This was working. But given the Japanese fighting spirit, likely tens of millions would have died before any change took place. It's also possible that the population could drop so low that the islands would become self-sufficient and then the war would drag on literally forever.

3. Conventional aerial bombardment. The Allies were already trying this with great gusto, to little diplomatic effect.

4. Demonstration nuke off the coast. The Allies only had two nukes left after the test one, and weren't 100% sure it would work. A failed demo would only strengthen Japanese resolve. There were concerns whether one demo nuke would be scary enough to force a surrender. Given that one actually used nuke wasn't, these concerns turned out to be valid.

5. Actually drop a nuke. This option turns out to have had the lowest bodycount in the end and had the unexpected side-effect of ushering in an unprecedented era of global peace.

Re: Super Heavy has splashed down in The Gulf of Mexico

#556

Post by pdonis »

FredPret wrote: post #541
xcv123 wrote: post #511

Earlier quoted context omitted.

Japan was already trying to negotiate conditional surrender when Hiroshima and Nagasaki were nuked. The US demanded unconditional surrender, and they nuked hundreds of thousands of civilians to force that demand. The bombing of Dresden is arguably a war crime by todays standards. It was unnecessary. Remember that we were allied with the Soviet Union (Joseph Stalin was the "good guy" on our side). After WW2 he was giv…

Conditional surrender would have been completely unacceptable given that they were the aggressor and had a million troops in China, and wanted to hold on to their conquests after the war. Even after the first nuke they didn't surrender. It took the emperor speaking up - for the first time ever - after the second nuke, and even then the military junta tried to stop it. Your points about the Communists stand, but keep…

> they were the aggressor

Only because the US froze all trade with Japan and intentionally refused all Japanese attempts at diplomacy to negotiate some kind of arrangement. The US did that knowing that the Japanese government would go to war, since the US had broken the Japanese codes and was reading all Japanese diplomatic traffic. In other words, the US intentionally provoked Japan into going to war.

Re: Super Heavy has splashed down in The Gulf of Mexico

#557

Post by avmich »

vl wrote: post #536
avmich wrote: post #441

Earlier quoted context omitted.

> Even if SpaceX will do orbital re-fueling, it's just two-three launches, why would you need more? Wikipedia says Starship weights 120 ton empty and 1320 ton fueled, plus 100 ton payload (approximate numbers). That means fuel weights 1200 ton. So to carry fuel to LEO to fuel up a Starship you need 1200 / 100 = 12 flights. You can change this number maybe 2 times into both directions, but I doubt you'll fuel Starship…

But you don’t have to fuel it fully to go to the moon and back. It’s a bit hard to compare to Apollo since Apollo dropped stages at every step of the process, but it seems they used 70 tons of fuel in the third state of Saturn V for original trans lunar injection of 45 ton Apollo. Apollo itself was 2/3 fuel. So it’s ratio of 15 tons to 90 tons. I.e. 1/6.

> But you don’t have to fuel it fully to go to the moon and back.

Numbers: from LEO (low Earth orbit) to TLI (translunar injection) - approx. 3.1 km/s; from Moon hyperbolic to LMO (low Moon orbit) - approx. 0.8 km/s; from LMO to the Moon surface - 1.6 km/s, back to LMO - 1.6 km/s, total - 7.1 km.s . Numbers are optimistic, no errors. You absolutely, positively have to add delta-V for landing, Apollo LEMs, for example, had ~0.6 km/s, and also for docking - about the same, so total is already 8.3 km/s . This is more than Starship needs to get to LEO after SuperHeavy boosted it from the Earth.

So... no, if you're planning to get to the Moon anything near the Starship regular payload - 100 ton - you absolutely have to fuel it up fully.

Re: Super Heavy has splashed down in The Gulf of Mexico

#558

Post by saati »

tialaramex wrote: post #219
SoftTalker wrote: post #186

Earlier quoted context omitted.

German V1 or V2, presumably.

Only the V2 is a rocket, the V1 is a flying bomb. They're both terror weapons, as actual products they have no direct military value, they exist solely in order to scare the shit out of enemy civilians, but liquid fuelled rockets are an invention with a whole lot of interesting practical applications - the V1 is just a bad idea (unless you have unlimited resources, which the Germans did not, and your goal is to terri…

The V1 is the ancestor of all cruise missiles, pretty far from no military value.

Re: Super Heavy has splashed down in The Gulf of Mexico

#559

Post by FredPret »

pdonis wrote: post #556
FredPret wrote: post #541

Earlier quoted context omitted.

Conditional surrender would have been completely unacceptable given that they were the aggressor and had a million troops in China, and wanted to hold on to their conquests after the war. Even after the first nuke they didn't surrender. It took the emperor speaking up - for the first time ever - after the second nuke, and even then the military junta tried to stop it. Your points about the Communists stand, but keep…

> they were the aggressor Only because the US froze all trade with Japan and intentionally refused all Japanese attempts at diplomacy to negotiate some kind of arrangement. The US did that knowing that the Japanese government would go to war, since the US had broken the Japanese codes and was reading all Japanese diplomatic traffic. In other words, the US intentionally provoked Japan into going to war.

Yes, they froze Japanese trade. But only to stop outrages being committed all over the area, including annexing Manchuria and invading China. The Japanese were doing all of this with imported US oil. Stopping the oil exports hardly places responsibility for Pearl Harbor on the US.

Re: Super Heavy has splashed down in The Gulf of Mexico

#560

Post by timschmidt »

MeImCounting wrote: post #529
somenameforme wrote: post #383

Earlier quoted context omitted.

Many basic materials, like water, make great shields if necessary. For Mars one plan is simply to organize the ship such that the water reserves can act as an radiation shield when necessary. You don't need anything particularly massive or overly fancy.

The problem is that paradoxically, thicker shields can cause higher doses of radiation due to secondary radiation production. Theres a balance there to minimizing primary and secondary dosage but you cant really get it below a certain threshold without some form of active shielding. Theres a lot of promising ideas for active shielding but they all require alot of power. All this to say that someone on a trip to mars…

https://en.wikipedia.org/wiki/Radiotrophic_fungus have also been discussed as an option.
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